noun
dialect; regional language
Refers to a regional dialect or local speech variety, often contrasted with standard language.
この地域の俚言を集めて辞書を作る。
We are compiling a dictionary by collecting the dialects of this region.
noun
colloquial language; slang; common speech
Refers to informal, everyday language used by ordinary people, including slang and colloquial expressions. Often used in linguistic or literary contexts.
彼の小説には当時の俚言がふんだんに使われている。
His novel is full of the colloquial language of that time.
The exact derivation is uncertain; the kanji 俚 (rustic, vulgar) and 言 (word, speech) combine to convey the idea of 'local or common speech'.